1. Field of the Invention
The present invention relates to digital video, and, in particular, to the insertion of logos into a compressed digital video bitstream.
2. Description of the Related Art
In the broadcast of normal analog (e.g., NTSC or PAL) television programs, it is common practice for the local broadcaster to insert its station logo on the network feed, for example, in a corner of the video display to identify the station. This is particularly true for cable television programming. This allows viewers to identify quickly what they are watching as they xe2x80x9cchannel surf,xe2x80x9d especially in these days when cable operators re-map channel assignments on their cable spectrum. A similar technique has recently come into use for TV program ratings, so that parents can immediately identify the rating of the program being watched. Inserting logos and other imagery into an incoming stream is very important in today""s video markets.
In future digital television systems, television programs will be transmitted from a central network to a local broadcaster as compressed digital video bitstreams conforming, for example, to an MPEG video compression standard. As is the case with uncompressed analog TV programming, it is desirable to enable local broadcasters to insert logos or other imagery into compressed digital video streams before broadcasting the TV programs to their customers.
The present invention is directed to a scheme for inserting logos or other imagery into compressed digital video streams. In one embodiment, one or more constraints are applied while generating a compressed digital video bitstream from an original video stream, wherein the constraints are selected to take into account a subsequent insertion of the imagery into the compressed digital video bitstream. Imagery-inserted encoded data is subsequently inserted into the compressed digital video bitstream to generate an imagery-inserted compressed bitstream without fully decoding the compressed digital video bitstream.